/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * This file is available under and governed by the GNU General Public
 * License version 2 only, as published by the Free Software Foundation.
 * However, the following notice accompanied the original version of this
 * file:
 *
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.objectweb.asm.tree.analysis;

import java.util.Set;
import org.objectweb.asm.tree.AbstractInsnNode;

/**
 * A {@link Value} which keeps track of the bytecode instructions that can produce it.
 *
 * @author Eric Bruneton
 */
public class SourceValue implements Value {

    /**
      * The size of this value, in 32 bits words. This size is 1 for byte, boolean, char, short, int,
      * float, object and array types, and 2 for long and double.
      */
    public final int size;

    /**
      * The instructions that can produce this value. For example, for the Java code below, the
      * instructions that can produce the value of {@code i} at line 5 are the two ISTORE instructions
      * at line 1 and 3:
      *
      * <pre>
      * 1: i = 0;
      * 2: if (...) {
      * 3:   i = 1;
      * 4: }
      * 5: return i;
      * </pre>
      */
    public final Set<AbstractInsnNode> insns;

    /**
      * Constructs a new {@link SourceValue}.
      *
      * @param size the size of this value, in 32 bits words. This size is 1 for byte, boolean, char,
      *     short, int, float, object and array types, and 2 for long and double.
      */
    public SourceValue(final int size) {
        this(size, new SmallSet<>());
    }

    /**
      * Constructs a new {@link SourceValue}.
      *
      * @param size the size of this value, in 32 bits words. This size is 1 for byte, boolean, char,
      *     short, int, float, object and array types, and 2 for long and double.
      * @param insnNode an instruction that can produce this value.
      */
    public SourceValue(final int size, final AbstractInsnNode insnNode) {
        this.size = size;
        this.insns = new SmallSet<>(insnNode);
    }

    /**
      * Constructs a new {@link SourceValue}.
      *
      * @param size the size of this value, in 32 bits words. This size is 1 for byte, boolean, char,
      *     short, int, float, object and array types, and 2 for long and double.
      * @param insnSet the instructions that can produce this value.
      */
    public SourceValue(final int size, final Set<AbstractInsnNode> insnSet) {
        this.size = size;
        this.insns = insnSet;
    }

    /**
      * Returns the size of this value.
      *
      * @return the size of this value, in 32 bits words. This size is 1 for byte, boolean, char,
      *     short, int, float, object and array types, and 2 for long and double.
      */
    @Override
    public int getSize() {
        return size;
    }

    @Override
    public boolean equals(final Object value) {
        if (!(value instanceof SourceValue)) {
            return false;
        }
        SourceValue sourceValue = (SourceValue) value;
        return size == sourceValue.size && insns.equals(sourceValue.insns);
    }

    @Override
    public int hashCode() {
        return insns.hashCode();
    }
}
